White-billed Buffalo-Weaver Bubalornis albirostris

Discovery

White-billed Buffalo-Weaver, figure from Temminck 1828

Temminck published 1st figure of the White-billed Buffalo-Weaver

White-billed Buffalo-Weaver distribution, type locality circled

Introduction

The White-billed Buffalo-Weaver was formally described by Louis Jean Pierre Vieillot, a French ornithologist. Vieillot also gave a French name to this species, ie. Le Gros-bec noir a bec blanc (meaning The black Grosbeak with a white beak).

Vieillot described the plumage of the White-billed Buffalo-Weaver and listed it from Africa. The type locality was later restricted to Senegal, based on the amount of white in the wing of this species.

This species was already described by Brisson 1760, based on specimens from coastal Africa, in the collection of Madame de Pompadour in 1754. Either Vieillot found these same specimens in the Paris museum and based his description on them, many decades later, or new specimens arrived from Africa.

The first illustration of this species to be published, was by Coenraad Jacob Temminck 1828, based on a specimen in the Paris museum, from Galam in Senegal. Again, there is the possibility that this is the same specimen as that of Brisson 1760, although Temminck provided his own name for the species.

1. Basic biology

White-billed Buffalo-Weaver,figure from wikipedia

White-billed Buffalo-Weaver,figure from specimen to show bill shape

Identification.
The White-billed Buffalo-Weaver Bubalornis albirostris is white-billed. The adult (photo above left) is black, with white feather bases showing through as small patches on the lower back, flanks and sides of breast; a white wing patch is visible in flight. The conical bill is white and swollen in breeding males (photo above right, from specimen 90331 in Leiden), otherwise black. The immature bird is dark brown with white mottling on the underparts. This species also has a phalloid organ (exposed in photo above left, see also Red-billed Buffalo-Weaver).

Distribution.
No subspecies of the White-billed Buffalo-Weaver are recognised. In the past it has been regarded as conspecific with the Red-billed Buffalo-Weaver. It occurs from Senegal across the savanna belt to western Ethiopia and Kenya (see map above, based on Birds of Africa). In 2009 it was recorded from Tanzania for the first time, from Naani Hill Gate, Serengeti National Park.

White-billed Buffalo-Weaver,colony in baobab

Habitat.
The White-billed Buffalo-Weaver inhabits dry savanna. In West Africa, it is found in very open farmland with patches of scrub, along streams and in belts of thorntrees. White-billed Buffalo-Weaver colonies are often in large trees, in or near villages. It is resident at its nesting colonies; when not breeding, birds forage away the nests but return before sunset to roost in the nest.

Food.
The White-billed Buffalo-Weaver feeds on seeds, including crops such as millet; also fruit, grasshoppers, termites, beetles and their larvae, and also small amimals such as frogs. They forage on the ground, search for insects in cowpats, and remove ectoparasites like ticks from cattle. Large noisy, feeding flocks may include individuals from several colonies. Chicks are fed on insects.

Breeding.
The White-billed Buffalo-Weaver is strongly colonial (eg. photo left). In a 50km transect survey in baobab savanna in Senegal, 31 trees had large colonies and 29 trees had small colonies; while in acacia savanna, 214 nests were counted in 24km.

The nest is a large compound structure, >1 m in diameter, containing up to 10 individual nest chambers. It is made of dry thorn twigs and branches, and lined with grass and green leaves. The nest is sometimes solitary. The nest entrance is sometimes surrounded by long thorny twigs sticking out. It is built mainly by the male and both sexes add lining. Males may steal material from neighbours, triggering raucous calling. Nest building activity often follows rainfall. In Tanzania, nests may be abandoned, then re-used in subsequent years.

Eggs (clutch 2-4) are whitish or pale greenish, heavily marked with grey and grey-brown. The female incubates the eggs and feeds the young.

2. Breeding facts

Pair bondPolygynous; colonialBreeding seasonJul-Sept throughout range; also Oct-Nov in some W African countries, mid Feb-Mar in Ethiopia and Eritrea; nest-building activity apparently stimulated by rainfallNest sitein thom trees up to 10 m above groundNest buildingmain structure built primarily by male, often stealing sticks from neighbouring nests, both sexes may add Iining materialColony sizewith up to ten individual nest-chambersClutch size2-4Egg colourwhitish or pale green to bluish, heavily blotched and spotted with grey and grey-brown (Nigeria), or plain to sparsely spotted with brown (Kenya)Egg sizeaverage for nine eggs in Nigeria 26.7 x 19.6 mmIncubationincubation of eggs by female only, no information on duration of incubation periodChicks and nestling periodfeeding of chicks by female only, no information on duration of nestling period; fledged young fed by both sexes

4. Breeding distribution

Google map showing distribution (For species with small ranges you need to zoom in at the correct area to see the range):
yellow blob - range of weaver species; read more about this here.
- PHOWN records with photos
- PHOWN records with no photos (Nest Record Cards, other records)
- Birdpix records
- comments on out of range records, or interesting records
- type locality
CLICK on the marker on the map to see individual record details.

5. Range changes

Not South African species

The above is based on Weaver Wednesday 3, a weekly series about range changes in South African weaver species.
This species text first appeared as
n/a